Handle exclusive end offsets when translating from flow thread coordinates.

third_party/WebKit/Source/core/layout/MultiColumnFragmentainerGroup.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MultiColumnFragmentainerGroup_h
 #define MultiColumnFragmentainerGroup_h
 
 #include "core/layout/LayoutMultiColumnFlowThread.h"
 #include "wtf/Allocator.h"
 
@@ skipping 44 matching lines @@
     // The bottom of our flow thread portion
     LayoutUnit logicalBottomInFlowThread() const { return m_logicalBottomInFlowThread; }
     void setLogicalBottomInFlowThread(LayoutUnit logicalBottomInFlowThread) { ASSERT(logicalBottomInFlowThread >= m_logicalTopInFlowThread); m_logicalBottomInFlowThread = logicalBottomInFlowThread; }
 
     // The height of our flow thread portion
     LayoutUnit logicalHeightInFlowThread() const { return m_logicalBottomInFlowThread - m_logicalTopInFlowThread; }
 
     void resetColumnHeight();
     bool recalculateColumnHeight(LayoutMultiColumnSet&);
 
-    LayoutSize flowThreadTranslationAtOffset(LayoutUnit, CoordinateSpaceConversion) const;
+    LayoutSize flowThreadTranslationAtOffset(LayoutUnit, LayoutBox::PageBoundaryRule, CoordinateSpaceConversion) const;
     LayoutUnit columnLogicalTopForOffset(LayoutUnit offsetInFlowThread) const;
     LayoutPoint visualPointToFlowThreadPoint(const LayoutPoint& visualPoint) const;
     LayoutRect fragmentsBoundingBox(const LayoutRect& boundingBoxInFlowThread) const;
 
     LayoutRect flowThreadPortionOverflowRectAt(unsigned columnIndex) const;
 
     // Get the first and the last column intersecting the specified block range.
     // Note that |logicalBottomInFlowThread| is an exclusive endpoint.
     void columnIntervalForBlockRangeInFlowThread(LayoutUnit logicalTopInFlowThread, LayoutUnit logicalBottomInFlowThread, unsigned& firstColumn, unsigned& lastColumn) const;
 
     // Get the first and the last column intersecting the specified visual rectangle.
     void columnIntervalForVisualRect(const LayoutRect&, unsigned& firstColumn, unsigned& lastColumn) const;
 
     LayoutRect calculateOverflow() const;
 
-    enum ColumnIndexCalculationMode {
-        ClampToExistingColumns, // Stay within the range of already existing columns.
-        AssumeNewColumns // Allow column indices outside the range of already existing columns.
-    };
-    unsigned columnIndexAtOffset(LayoutUnit offsetInFlowThread, ColumnIndexCalculationMode = ClampToExistingColumns) const;
+    unsigned columnIndexAtOffset(LayoutUnit offsetInFlowThread, LayoutBox::PageBoundaryRule) const;
 
     // The "CSS actual" value of column-count. This includes overflowing columns, if any.
+    // Returns 1 or greater, never 0.
     unsigned actualColumnCount() const;
 
 private:
     LayoutUnit heightAdjustedForRowOffset(LayoutUnit height) const;
     LayoutUnit calculateMaxColumnHeight() const;
     void setAndConstrainColumnHeight(LayoutUnit);
 
     LayoutUnit rebalanceColumnHeightIfNeeded() const;
 
     LayoutRect columnRectAt(unsigned columnIndex) const;
@@ skipping 53 matching lines @@
 
 private:
     LayoutMultiColumnSet& m_columnSet;
 
     Vector<MultiColumnFragmentainerGroup, 1> m_groups;
 };
 
 } // namespace blink
 
 #endif // MultiColumnFragmentainerGroup_h